First results

[Peter Finke]

The first genetic investigations on Parosphromenus were executed by Britz and Rüber at the Natural History Museum London more than ten yeras ago on rather a small smaple material. Now we have first results of the DNA-analysis that has been done in Guelph (Canada) by Dr. Dirk Steinke on the basis of many samples that have been sent in by members of the Parosphromenus-Project from 2005 till 2009. All decribed species have been analyzed with the exception of allani. A first “tree-structure” of the genus has been sketched, but it is preliminary.
The clearest result matches our hypotheses from the observatin of phenotypes and behaviour: The two slim species ornaticauda and parvulus seem clearly to be separated from the rest of the genus – whatever that means. But there was only one sample of parvulus. Surely, we can say some more things in the next time. One has to keep in mind that in Canada a very special method was applicated that was concentrating on a small fragment of the whole DNA, following the hypothesis that this fragment contains the whole species-information.
Presently, the investigations are continued in Switzerland at the Museum for Natural History in Bern by Dr. Lukas Rüber. Lukas applies a different method so we can perhaps evaluate the relative power of the methods. Among the first findings we heard that parvulus and linkei from different locations appear to be genetically different, too. This might be correlated with different phenotypical markers, but it is too early to say more.

[Gregor Mecklenburg]

Hello Peter,

I like the way how the parosphromenus-project is trying to go beyond just the private keeping and breeding of these fish. It does seem like a quite ambitious network around this genus or these genera.

Who initiated these genetic investigations and/or payed for them? I am assuming that this type of scientific work may not be free of charge.

Only recently I started wondering about a few questions loosely related to this subject here, concerning the scientific work with and around new or known species. Maybe this is a good place to ask.

For example:

– Who decides, when it is time for a newly discovered species to be scientifically described as such…
– …and by whom it is to be described?
– Who decides, what name it is to be officially given?
– What is it that determines an official, scientifically acknowledged status of a description/species?
– Are these official descriptions of species being checked on a regular basis, compared to recently collected samples and maybe corrected or updated if necessary?
– Are the fish in captivity regularly compared to wild representatives of their species to notice any possible genetical or phenotypical changes in either population?

Maybe this is all common knowledge but I just haven’t come across it yet.
If these questions appear not to be fitting in this thread, maybe they can be moved to a different place within the forum.

Thanks for your time and thoughts!
Just trying to learn 🙂
Gregor

[Peter Finke]

Greg, please understand that I cannot reply to your many questions in detail here. But I shall try to do so in a more general way.
1. The genetic investigations were initiated by a group of young ichthyologists from the Natural History Museum in London and by myself and some others. I have contacted Dr. Steinke who first worked in Germany before he went to Guelph in Canada in order to work for the Fish-BOL-project. They investigate in sea-fish in the first line, but Steinke was interested privately in our question and he did that without any costs beside his official duties. The same happens now in Bern with Dr. Rüber, one of the London team, who has returned to his home Switzerland. He has taken over now from Steinke. All this is without any costs for us.
2. On description: There is nobody officially deciding what should be described or who should do that. In principle every person could do it when he thinks he is able to. But the thing is not easy. We have some descriptions that therefore have remained rather preliminary (harveyi, nagyi …). But they are valid nevertheless. In the last cases the thing was done mainly by Maurice Kottelat, a good expert on south-east Asian fish. But now there seems to be a delay of further descriptions. One can presume for what reasons … And the describer decides on the name. Once the name is given and the descriptions is published, it is final.
A description is official when the name is given and when it is published. There are many things that should be included in such descriptions, but if they miss, the thing is valid nevertheless. That’s a big problem. There is no official “check” or control. But from time to time a scientist who is interested in that genus and thinks to have found some faults or deficiencies decides personally to try a revision of that genus. But it is entirely a matter of personal decision and faculty.
3. Are the fish in captivity regularly compared to wild representatives of their species to notice any possible genetical or phenotypical changes in either population? No, not at all. But the best experts of a genus (and we have all in our project) try to do that as often they have the possibility for it. But that could not be done systematically. Only if they come across some “strange” deviant fish … In our Parosphromenus-project we have some very good experts on our genus who can tell you of many variants and of many questions and problems of the official descriptions.
4. So there is certainly a great need for a revision sometime in the future. And the inclusion of genetic methods will play a big role in that for the hitherto decriptions are restricted to the phenotypes only. Mostly on dead museum-matarial. Even behaviour is nearly not discussed at all… So, for instance, displaying males with head-down and displaying males with head-up are not taken to indicate an important feature for the description. This will surely be an important point in a future revision of Parosphromenus.

[Gregor Mecklenburg]

Thanks a lot Peter.

You have given me a good first idea of how things are basically handled.

Understanding seems impermanent. New methods and new “facts” lead to new knowledge. I guess that having to accept the “final “preliminarities”” can be frustrating but learning about new details can be a joy as well 🙂
It is wonderful that you have found experts to personally engage in research concerning Parosphromenus.

Have a good weekend,
Gregor

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